1. Field of the Invention
The present invention relates to image processing methods and apparatuses and to programs. More specifically, the present invention relates to an image processing method and apparatus and a program with which the resolution of an image is converted in each block of a predetermined size based on an amount of movement before the image is output.
2. Description of the Related Art
Recently, digital video cameras often include imaging devices having a resolution higher than a resolution for recording moving images, mainly for the purpose of capturing high-definition still images. In such digital video cameras, when recording moving images, conversion from an imaging resolution to a recording resolution, i.e., reduction in resolution, is needed.
As methods for reducing resolution in solid-state imaging devices such as charge coupled device (CCD) imaging devices or complementary metal oxide semiconductor (CMOS) imaging devices, for example, a method of decimating imaging pixels for reading by controlling a driving method, and a method of summing signals of a plurality of pixels for reading, as disclosed in Japanese Unexamined Patent Application Publication No. 11-331706 and Japanese Unexamined Patent Application Publication No. 2003-78919, are known.
It is known that CCD imaging devices or CMOS imaging devices allow imaging at a high frame rate when the devices are driven at a high speed.
As methods for allowing an observer of an image displayed on a display to perceive the image at a resolution exceeding an actual resolution of the image, according to a first method disclosed in Japanese Unexamined Patent Application Publication No. 6-18836, a plurality of liquid crystal display elements is used, and images are combined while optically shifting positions using half mirrors or the like. According to a second method disclosed in Japanese Unexamined Patent Application Publication No. 6-324320, what is called wobbling is performed, i.e., the optical axis of light coming from liquid crystal display elements is optically vibrated to shift pixel positions. Perception of an image by an observer at a resolution exceeding an actual resolution of the image displayed will hereinafter be referred to as a super-resolution effect.
However, conversion of resolution by decimation causes decrease in sampling rate and therefore causes aliasing, causing degradation in the quality of moving images. Furthermore, conversion of resolution by summing pixel signals limits resolution by output resolution.
As for the first method mentioned earlier, in order to achieve high resolution, a plurality of display elements, and optical elements for combining lights output from the plurality of display elements, are needed. Thus, cost of the apparatus is high, the structure is complex, and compact design is inhibited.
As for the second method mentioned earlier, in order to achieve high resolution, optical elements for optically shifting an optical axis is needed. This leads to increased cost due to the optical elements for wobbling, and requires a complex driving method.